1. Field of the Invention
The present invention pertains to the closure of flexible packages, such as plastic bags, and in particular to fastener closures employing sliders.
2. Description of the Related Art
With the ongoing emphasis in providing consumers with bulk quantities of various commodities, such as food products, reclosable packages have become increasingly popular. One of the most popular means of providing reclosability is to employ zippers of various types, particularly zippers which are compatible with flexible packages of plastic film construction. Manufacturers of food products and other commodities are concerned with filling the contents of a flexible package as quickly and economically as possible. It is important that the opening provided by the fastener be made as large as practically possible. Consumers or other end users also prefer large sized openings for easy extraction of products from the package interior. Even with large openings, however, products within the package may interfere with fastener operation when product poured or otherwise dispensed from the package becomes entrained in the fastener components.
Although improvements have been made in the art of making plastic bags, improvements are continually being sought. For example, bags having slide fasteners are employed in a wide variety of consumer products. When bags of this type are employed for sensitive consumer products, such as food products it is desirable to protect the opening of the bag from dust and other material associated with casual contact of the bag, during shipment and handling. It has been found convenient to employ sliders which traverse the interlocking fasteners, assuring complete inter-engagement of the fastener tracks with a minimum of manual dexterity. Sliders of increased width are popular, especially with young children and elderly consumers. In providing an over-covering for the slider it has been convenient to extend film comprising the side walls of the bag upwardly over the slider to form a shroud. Although economical, this technique causes tension in the plastic film due to the tight capture of the relatively massive slider between the sheets of plastic film. Holes have been formed in the shroud to serve as a tension relief for sliders which protrude partially or entirely through the hole.